Generally, an LED lamp consumes extremely low power and has a quite long lifespan compared with a halogen or neon lamp and, in addition, is advantageous in that it may produce further diverse colors compared particularly with a fluorescent or halogen lamp.
In addition, the LED lamp is configured by arranging LED modules having a plurality of LEDs in a specific array and installing the LED modules on the ceiling or a wall, and since the LED lamp generates a considerably large amount of heat by the nature of the LED element when LED lamp is driven, heat dissipation is a problem that should be solved, and a metal PCB has been developed recently to solve the problem.
In addition, the metal PCB is structured by forming a trench having a predetermined depth, forming terminals through electrolytic plating, uniformly arranging a plurality of LED elements inside the trench, and then connecting the LED elements with each other or connecting the LED elements and the terminals through wire bonding.
Then, the LED module is formed by filling a fluorescent material in the trench of a comparatively large area where the plurality of LED elements are arranged and filling optically transparent resin up to the surface to include a portion in which the terminals are formed on the trenched Pattern.
In relation to this technique, Korean Patent No. 1105454 discloses a technique of a printed circuit board for an LED lighting apparatus and a manufacturing method thereof, and as shown in FIG. 1, it is schematically configured of a heat sink plate 10, an insulation substrate 20, an insulation film 30 and a metal thin film 40, and a plating prevention layer 50 of the same size is formed on the bottom surface of the heat sink plate 10 to prevent plating.
In addition, the heat sink plate 10 is made of a metal material having a shape of a plate, and the insulation substrate 20 is formed to have an outer diameter the same as that of the heat sink plate 10 and a thickness thinner, if possible, than that of the heat sink plate 10, and a plurality of first holes 21 is formed to vertically penetrated the heat sink plate 10 and the insulation substrate 20.
Then, connection terminal pads 23 are formed on the surface of the insulation substrate 20 together with a circuit pattern, and second holes 41 are formed on the surface of the metal thin film 40 on a concentric circle of the first holes 21 formed on the insulation substrate 20, and the second holes 41 are installed to upwardly expose the connection terminal pads 23 formed on the peripheral side of the first holes 21 of the insulation substrate 20.
Then, the LED lighting apparatus is provided by inserting LED elements in the first holes 21 of the insulation substrate 20, filling a fluorescent material in the first holes 21 where the LED elements are inserted, and filling an optically transparent molding material in the second holes 41 formed on the metal thin film 40 on the top of the first holes 21.
However, since the printed circuit board described above should be provided with the heat sink plate 10 for dissipating heat and the metal thin film 40 for connecting power, it is disadvantageous in that the PCB is difficult to manufacture, and additional parts are required.
Furthermore, the insulation layer should be formed to configure a pattern of the PCB, and the insulation layer operates as an insulator for blocking a passage which transfers the heat generated by the LED elements to the metal thin film 40, and thus it is disadvantageous in that the heat may not be effectively discharged outside.